Typically, manufacturers of application specific circuits will design a distinct PC board for each required circuit application. The number of specific PC boards manufactured is then determined by the number required for that specific application. The manufacturing cost of a printed circuit board (PC board) is directly related to its volume of manufacture. When the specific application requires a small number of PC boards, the cost per board can be quite high.
In the area of automatic transmission or power train controls, for example, it is often necessary for a single electronic control module to control as many as ten or more different solenoids or, depending on the specific transmission control application, as few as one or two solenoids. Moreover, in addition to the different numbers of solenoids that must be controlled in different circuit applications, there are also two principal types of solenoid control: proportional control and binary (ON/OFF) control. In any given transmission control application there can be many different combinations of the number and types of solenoid controls that must be implemented by the solenoid driver circuitry. Generally, each of those specific solenoid driver applications requires a different PC board and its limited application makes each board costly.
Additionally, it is often necessary to protect the machine and the controlled device, for example, the transmission, solenoids and controller from certain failures, for example, shorts to electrical ground, shorts to battery voltage and open circuits failures. Typically this is accomplished via failure detection circuitry or a combination of circuitry and software routines in a controller. However, the required circuitry and diagnostic scheme is different between the driver types.
The present invention is directed to overcoming one or more of the problems, as set forth above.